HI @BorjaCorrea -
When you assign someone to a people column, it already subscribes them to the pulse, so I think you are trying to subscribe them without having them already assigned, yes?
Unfortunately, the only way to do this is to hardcode that in an automation as follows:
It’s encouraged that in the someone field, that you use Subscribers > Board Subscribers, so you don’t have to truly hardcode, but you can hardcode to a specific person using this, without any people fields already populated on the pulse (because it’s new).
I did JUST test this with a second user account (hard-coded in the automation - by name) and the notification setting “Notifies me via automations” is selected as it should be on the user profile. The notification does fire to my second (testing) account, but it takes a few minutes.
Hope this info helps you, if not… I recommend putting a support case in with Monday, they are super helpful!